1. Technical Field
The present disclosure relates to a gate driver that drives a field-effect transistor, and a power module equipped with the same.
2. Description of the Related Art
Silicon carbide (SiC) is a semiconductor material with a larger bandgap compared to silicon (Si), and is applied to power devices. Power devices that use SiC include, for example, the metal-insulator-semiconductor field-effect transistor (MISFET) (see International Publication No. 2010/125819 and Japanese Unexamined Patent Application Publication No. 2010-509771, for example). The metal-oxide-semiconductor field-effect transistor (MOSFET) is one type of MISFET.
International Publication No. 2010/125819 discloses a field-effect transistor equipped with a channel layer. In the field-effect transistor, when the gate-source voltage is less than a gate threshold voltage, a current flows from the source to the drain if the drain-source voltage is a negative voltage. At this point, since the current passes through the channel layer, the transistor is called a channel diode. International Publication No. 2010/125819 discloses using a channel diode as a flyback diode. Note that in this specification, the drain-source voltage refers to the voltage of the drain with respect to the source. Also, the gate-source voltage refers to the voltage of the gate with respect to the source.
In a field-effect transistor, on/off control is conducted using a voltage applied between the gate and the source. When switching a field-effect transistor from the on state to the off state, suppressing misfiring due to noise and the like by applying a negative voltage between the gate and the source has been proposed (see Japanese Unexamined Patent Application Publication No. 5-244765 and International Publication No. 2009/004715, for example).
International Publication No. 2010/125819, Japanese Unexamined Patent Application Publication No. 2010-509771, Japanese Unexamined Patent Application Publication No. 5-244765, and International Publication No. 2009/004715 are examples of related art.